Compositions comprising anti-drift agents and processes and methods for their use

ABSTRACT

A composition (1) comprising water, in solution, 
     a) an inorganic water-soluble compound in an amount of at least 10%, 
     b) an anti-drift agent which is a water soluble anionic polymer of intrinsic viscosity at least 6 dl/g which is formed from water soluble monomer or monomer blend, 
     characterized in that the water-soluble polymer (b) is present in an amount up to 1.9 wt. % based on weight of composition. 
     Said composition (1) can be a liquid fertilizer concentrate that can conveniently be applied through conventional spray distribution equipment without the need for additional dosing of anti-drift control chemicals. Said composition (1) can be a low viscosity liquid anti-drift agent that can be combined with a herbicide or pesticide in conventional spray distribution equipment.

This invention relates to novel aqueous compositions that compriseanti-drift agents and inorganic water-soluble compounds, which canconveniently be applied using conventional spray distribution equipment.The invention also relates to processes of spraying fertilisers,herbicides and pesticides in which the novel compositions are used andmethods of reducing spray drift during the spraying process.

It is well known in agriculture to apply various agrochemicals togrowing areas by spraying. The growing areas may be crop areas, whichcan be very large, or smaller growing areas such as those ingreenhouses. The agrochemicals applied as sprays include fertilisers,herbicides and pesticides.

Fertilisers can be supplied in various forms, in particular as solidcompositions, or as suspensions or solutions of the fertiliser in aliquid. Fertiliser solutions are generally supplied by the manufactureras an aqueous concentrate in large batches of size around 1 ton inweight. The solutions contain high concentrations, often 10 to 80 wt. %(dry solids), of dissolved inorganic fertiliser.

Herbicides and pesticides can be supplied to the farmer in variousforms, for instance as neat liquids, aqueous solutions, aqueousdispersions or slurries of solid herbicide or pesticide. It is normalpractice for the manufacturer to supply the farmer with the herbicide orpesticide in the form of a neat liquid or as a high activity solution orslurry. The usual way of applying herbicides or pesticides to an area ofland would be by spraying.

Various systems have been devised for convenient dosing of fertilisers,herbicides or pesticides. Spray pumps are well known which spray waterfrom a spray manifold onto the area of land or crop area and which aredesigned so that concentrated fertiliser solution, herbicide orpesticide can be dosed into the pump, mixed with water before beingsprayed.

For some applications it is usual to combine two or more agrochemicals.For instance in the application of herbicides, especially systemicherbicides, it is usual to combine the treatment with a fertiliser, suchas for instance ammonium sulphate. The fertiliser stimulates the growthof unwanted plants causing them to take up much more water, togetherwith the herbicide, through the root system. This ensures a moreefficient uptake and distribution of herbicide throughout the plant. Inthis instance the fertiliser may be regarded as an adjuvant in that itincreases the efficacy of the herbicide. Thus a fertiliser used incombination with a herbicide is termed a herbicide adjuvant.

During the spraying of fertilisers, herbicides and pesticides it isusual to apply anti-drift agents in order to prevent the formation offine droplets which could be carried beyond the area intended to betreated. Without the use of anti-drift agents, the spraying offertilisers, herbicides and pesticides would be inefficient, first ofall because there could be inadequate treatment of the land and cropareas intended to be treated and secondly the extraneous spray, ifcarried beyond the intended treatment zone, could for example bedetrimental to other crops, land and water courses.

It is usual to combine the anti-drift agent with either the water whichis fed into the spray pumps or to apply it directly into the spraypumps, usually at or shortly after the mixing zone where the water ismixed with the herbicide, pesticide or aqueous fertiliser concentrate.It is important that the spray drift chemical is metered at the correctdose to ensure that extraneous spray is not formed through under dosingor through overdosing the spray angle is too narrow resulting in unevendistribution of the pesticide, herbicide or fertiliser.

Polymers of acrylamide and other ethylenically unsaturated monomers havebeen used as anti-drift agents. It has been generally accepted thatpolymers which give optimum spray drift control are either non-ionic (egacrylamide homopolymer) or have relatively low anionic content (e.g. 5to 30 wt. %) and also have relatively high intrinsic viscosity, forinstance above 6 dl/g. Such polymers tend to form viscous aqueoussolutions unless used at low concentration. Normal practice is to mixthe polymer powder or reverse phase emulsion form with water directlyinto the spray tank so as to form an aqueous solution of polymer.However, this has the problem that emulsion polymers can be difficult toactivate in this situation and polymer powders take a long time todissolve. It is sometimes necessary to use more polymer as a result ofinefficient dissolution of the polymer. Normally in order to minimisethe problems with dissolution it would be usual to use polymers ofintrinsic viscosity in the range 6 to 15 dl/g. Typically the watercontaining the pesticide, herbicide or fertiliser would comprise polymerat a concentration in excess of 0.05 wt. %.

It would be desirable to provide a combined fertiliser compositioncomprising anti-drift agents that can conveniently be applied throughconventional spray distribution equipment without the need for separatedosing of anti-drift control chemicals. It would also be desirable toprovide a means for reducing spray drift during the spraying ofherbicides or pesticides by conveniently applying a low viscosity, highactivity liquid anti-drift control composition.

One aspect of the invention relates to an aqueous composition comprisingwater, in solution,

a) an inorganic water-soluble compound in an amount of at least 10% byweight,

b) an anti-drift agent which is a water soluble anionic polymer ofintrinsic viscosity at least 6 dl/g which is formed from water solublemonomer or monomer blend,

characterised in that the polymer (b) is present in an amount up to 1.9wt. % based on weight of composition.

In a preferred embodiment of the invention the inorganic water-solublecompound is used as a fertiliser. Thus this aspect of the inventionrelates to a single pack product which provides a combined fertiliserwith anti-drift agent that can conveniently be applied throughconventional spray distribution equipment and negates separate dosing ofadditional anti-drift control chemicals. It can be produced by addingpolymer (b) to a standard concentrated solution of an inorganicwater-soluble salt which is a fertiliser. The amount of polymer used issufficient to minimise spray drift after dilution of the concentratedsolution in the standard manner for fertiliser solutions.

In another aspect of the invention the inorganic water-soluble compoundis used as a herbicide adjuvant. The composition of this aspect of theinvention enhances the activity of a herbicide with improved anti-driftproperties and can be conveniently applied through conventional spraydistribution equipment. It can be produced by adding polymer (b) to astandard concentrated solution of an inorganic water-soluble salt whichis a herbicide adjuvant, at a concentration that will minimise spraydrift after dilution of the concentrated solution in the standard mannerfor herbicide adjuvant solutions.

It has surprisingly been found that effective spray drift control whenspraying pesticide, herbicide or fertiliser can be provided usingconcentrations of anionic water soluble polymer up to 0.065% based ontotal weight of dilute aqueous pesticide, herbicide or fertiliser beingsprayed, using the aqueous composition comprising at least 10 wt. %inorganic water-soluble salt and up to 1.9 wt. % of an anionic watersoluble polymer of intrinsic viscosity of at least 6 dl/g. Furthermore,effective drift control can be achieved by using the water solubleanionic polymers at concentrations of below 0.025%, often below 0.01%,for instance in the range 0.001% to 0.0095%, especially in the range0.0025% to 0.0075%, based on total weight of dilute aqueous pesticide,herbicide or fertiliser being sprayed.

It has also surprisingly been found that spray drift control is lessdose sensitive when using the aqueous composition of the invention.Provided that the minimum amount of anti-drift agent is used, a muchwider range of doses will achieve adequate spray-drift control withoutsuffering the effects of overdosing. This is of significant benefit tothe farmer in that it ensures a more effective treatment of a crop areaor an area of land. By contrast conventional methods of applyinganti-drift agents are much more dose sensitive and in order to ensure norisk of spray drift there can be a tendency to overdose, which wouldresult in a narrower spray angle and the consequential inefficientdistribution of pesticides, herbicides and fertilisers.

The invention provides an aqueous composition in which the definedpolymer (b) is preferably substantially dissolved. That is, the polymeris taken into the solution such that substantially no visible solidmaterial remains.

The polymer must be substantially water soluble and in particular issoluble in the aqueous solution of inorganic water-soluble salt havingthe same concentration of inorganic water-soluble salt as the aqueouscomposition which is desired to be produced. Generally the polymer issubstantially linear and is not cross-linked.

The polymer has intrinsic viscosity at least 6 dl/g. In thisspecification intrinsic viscosity is measured by suspended levelviscometer at 20° C. in 1 M sodium chloride buffered to pH 7. That is ofsufficiently high molecular weight to give spray drift controlproperties and is not a low molecular weight material which would act asa dispersant.

Preferably IV is at least 8 dl/g, more preferably at least 9 dl/g. Itmay be up to for instance 30 dl/g but generally it is found that theoptimum combination of low viscosity of the composition and spray driftcontrol performance is given by polymers having IV not more than about20 or 18 dl/g. Preferably IV is not more than 16, more preferably notmore than 15 dl/g. Particularly preferred IV ranges are from 9 to 13dl/g, especially 10 to 12 dl/g.

The polymer is formed from water soluble monomer or monomer blend,usually water soluble ethylenically unsaturated monomer. The anioniccontent i.e. the proportion of anionic monomer in the monomer blend usedto form the polymer, is at least 15 wt. %. It can be up to 100 wt. %,but is preferably not more than 80 wt. %, more preferably not more than70 wt. %, most preferably not more than 60 wt. %. Particularly preferredpolymers have anionic content in the range 20 to 50 wt. %, morepreferably in the range 25 to 30 wt. %.

The monomer or monomer blend used to form the polymer comprises anysuitable anionic ethylenically unsaturated monomer. It can be asulphonic monomer, often as sodium or other alkali metal salt, forinstance 2-acrylamido-2-methylpropane sulphonic acid. It is generallypreferred that the anionic monomer is an ethylenically unsaturatedcarboxylic monomer, in particular acrylic or methacrylic monomer. Saltsof acrylic acid are preferred, for instance ammonium or alkali metal, inparticular sodium salts.

The polymer may contain small amounts of cationic monomer, for instanceup to 20 wt. % or 10 wt. % but usually the content of cationic monomeris substantially zero.

Generally the anionic monomer is copolymerised with nonionic monomer,usually ethylenically unsaturated water soluble non-ionic monomer suchas acrylamide or methacrylamide, preferably acrylamide. Particularlypreferred polymers are copolymers of acrylamide with sodium acrylate.

The polymer is included in the composition in an amount such that whenthe composition is diluted for spraying, it provides adequate spraydrift control performance. Polymer concentration in the aqueousfertiliser composition is generally up to 1.9 wt. %, for instance below1.0 wt. %, preferably below 0.5 wt. %, more preferably below 0.2 wt. %,more preferably below 0.15 wt. %. Particularly preferred compositionscomprise polymer concentrations in the range 0.05 wt. % to 0.1 wt. %.

The aqueous composition of the invention can be made in any convenientmanner. For instance polymer may be added to water followed byfertiliser or the two may be added simultaneously. Alternatively,fertiliser may be added to a preformed solution of polymer. However,generally it is preferred that polymer is added in solid form, ie powderor bead. It is possible to add it in other forms, such as reverse phasedispersion, but solid is preferred. Preferred solids are in the sizerange 70 to 2,000 microns and are made in a standard manner, forinstance by suspension polymerisation to provide polymer in bead form orby solution polymerisation, followed by comminution and drying, toprovide polymer in powder form.

Thus the invention relates to a process for the production of an aqueouscomposition of the invention comprising providing a preformed aqueoussolution of the fertiliser (a) and mixing into it polymer (b) in powderform.

The thus formed composition should have viscosity which renders thecomposition easy to handle. It should in particular be easy to handle(i.e. preferably pumpable, pourable or sprayable) in the equipment whichis presently used for spraying. The polymer may be added to thefertiliser at the facility of the fertiliser manufacturer and thus theviscosity should be low enough that the resulting solution can behandled by equipment presently in place in such facilities. Preferablyviscosity is below 3,000 cPs, more preferably not more than 1,000 cPs.In particular it is not more than 500 and especially not more than 250cPs. Particularly preferably it is not more than 100 cPs. Usually it isin the range of 5 to 50 cPs, preferably 10 to 30 cPs, more preferably inthe range 15 to 20 cPs. In this specification viscosity is measuredusing a Brookfield LVT viscometer using spindle 4 at 30 rpm.

Thus aqueous composition of the invention may be sprayed directly ontoan area of land or especially a crop. However, the composition of theinvention is intended particularly as a concentrate for use in dilutedcompositions to be sprayed.

Prior to spraying, the aqueous composition of the invention will bediluted with water and optionally additional agricultural chemical willbe added. Typically the aqueous composition of the invention is dilutedto a concentration of below 10 wt. % based on total weight of diluteproduct to be sprayed. Preferably the composition of the invention isdiluted to between 1 and 5 wt. %, more preferably 2 to 3 wt. %, mostpreferably about 2.5 wt. %.

The composition comprises an inorganic water-soluble compound insolution. The inorganic water soluble compound is preferably afertiliser or herbicide adjuvant. In many instances fertilisers andherbicide adjuvants would be the same selection of compounds. Thefertiliser or herbicide adjuvant is present at a concentration of atleast 10 wt. % and is usually as high as is convenient, for instance atleast 20 wt %. Preferably it is at least 30 wt. %. It can be as high as70 or 80 wt % but is usually not more than 60 wt. %. Preferredconcentration ranges are 30 or 40 to 55 wt. % for instance around 50 wt%.

Urea and any of the known inorganic fertiliser materials can be used,which provide nitrogen, phosphorus and/or potassium either alone or inmixture. These contain ionic salts and include ammonium nitrate,ammonium sulphate, mono ammonium phosphate, diammonium phosphate, monopotasssium phosphate, dipotassium phosphate, polyphosphate salts,potassium chloride, potassium sulphate and calcium nitrate. Aparticularly preferred fertiliser and herbicide adjuvant is ammoniumsulphate.

Examples include urea/ammonium nitrate (32-0-0), potassium chloride(0-0-10), ammonium sulphate (8-0-0-9S), a blend of calcium and ammoniumnitrate, and blended fertilisers with the following analyses: 19-0-8,10-0-10, 3-18-18,0-0-25-17S, 10-10-10 and 14-2-10-2+2.5% organic matter(OM).

The fertiliser composition of this invention may also be used incombination with one or more other agricultural chemicals, for instanceherbicides or pesticides, especially systemic herbicides, such asglyphosate or glufosinate. A particularly preferred composition forspraying comprises ammonium sulphate and glyphosate. The additionalagricultural chemical(s) would generally be combined with the fertilisercomposition during the spraying process. They may be applied as aseparate feed into the dilution water or directly into the sprayequipment. For instance the additional agricultural chemical may becombined with the fertiliser slightly ahead of or directly into themixing zone within the spray distribution equipment.

The invention is particularly useful when it is known to be desired toapply a particular fertiliser by spraying and where the spraying wouldbe facilitated by not requiring a separate dosing of anti-drift agent.It is of additional value when the fertiliser composition is used incombination with other agricultural chemicals, for instance herbicidesand pesticides.

Preferably the aqueous fertiliser composition of the invention is anaqueous fertiliser concentrate. Prior to spraying, the aqueousfertiliser concentrate of the invention will be diluted with water.Typically the concentrate can be diluted to a concentration of below 10wt. % based on total weight of dilute product to be sprayed. Preferablythe aqueous fertiliser concentrate is diluted to between 1 and 5 wt. %,more preferably 2 to 3 wt. %, most preferably about 2.5 wt. %.

The optimum polymers may vary according to the specific inorganicwater-soluble compound or combination of inorganic water-solublecompound with additional agricultural chemical.

In general polymers of anionic content of at least 15 wt. % are moresoluble in the solution of inorganic water-soluble salt, and are thusmore effective as anti-drift agents in this invention. Preferably theanionic polymers used in the composition of this invention have ananionic content in the range 15 to 50 wt. % especially 25 to 30 wt. %.

Desirably the aqueous composition may comprises at least 10 wt. %ammonium sulphate in solution together with up to 1.9 wt. % watersoluble anionic polymer of intrinsic viscosity between 8 and 30 dl/g andan anionic content of above 15 wt. %. Preferably the water solubleanionic polymer has an intrinsic viscosity between 8 and 20 dl/g and ananionic content of above 15 wt. %. Preferably the concentration ofammonium sulphate is at least 30 wt. %. More preferably the polymer hasan intrinsic viscosity between 10 and 15 dl/g. Typically the anionicpolymer is present in an amount below 1.0 wt. % based on total weight ofcomposition, preferably below 0.5 wt. %. Particularly preferred is acomposition in which the anionic water soluble polymer is present in anamount below 0.2 wt. % based on weight of composition, preferably below0.15 wt. %. More preferred is a composition where the concentration ofanionic polymer is present in an amount between 0.05 wt. % and 0.1 wt. %based on total weight of composition. Typically the composition wouldcomprise an anionic polymer of which the anionic content is between 20and 50 wt. %, preferably 25 to 30 wt. %, based on total weight ofcomposition. Most preferred would be a composition comprising acopolymer of acrylamide with acrylic acid, or alkali metal or ammoniumsalt thereof. Preferably the composition is prepared by adding solidanionic polymer to a solution of ammonium sulphate solution.

Another advantage of the present invention is that the efficacy ofherbicides, especially systemic herbicides, for instance as glyphosateor glufosinate has surprisingly been found to be synergisticallyenhanced, when used in the composition of the present invention. It isbelieved that the a water soluble anionic polymer may be acting as anadjuvant. This improvement in efficacy has been observed for variousanionic water soluble polymers of intrinsic viscosity at least 6 dl/g,for instance polymers of acrylamide with acrylic acid containing atleast 25% by weight anionic monomer units. The proportion of anionicunits may even be as high as 60 or 70% by weight and in some instanceseven higher.

It may also be desirable to further enhance the efficacy of thecomposition by including other ingredients. For instance it may bedesirable to include a reverse phase anionic or nonionic polyacrylamideinto the aqueous composition, such as described in U.S. Pat. No.5,529,975, incorporated by reference herein. Alternatively an additionalingredient may suitably be a low intrinsic viscosity anionic or nonionicpolyacrylamide aqueous polymer, for instance as described in U.S. Pat.No. 5,525,575, incorporated herein by reference. If additionalingredients are included in the aqueous formulation, generally theywould be included in an amount of 0.005 to 0.2% by weight of sprayableformulation.

Another aspect of the invention provides a process of applyingfertiliser to an area of land or a crop area comprising spraying waterto which has been added an aqueous composition comprising water, insolution,

a) an inorganic water-soluble compound in an amount of at least 10%,

b) an anti-drift agent which is a water soluble anionic polymer ofintrinsic viscosity at least 6 dl/g which is formed from water solublemonomer or monomer blend,

characterised in that the polymer (b) is present in an amount up to 1.9wt. % based on weight of composition and wherein the inorganic compound(a) is the fertiliser.

In a preferred aspect of the process for the application of fertiliser,water is pumped through a feed ducting and a mixing zone to a spraymanifold supplying one or more spraying devices by which the water issprayed onto a crop area and the above aqueous composition is meteredinto the water at or before the mixing zone,

In the process of applying a fertiliser the polymer (b) is preferablyformed from water soluble monomer or monomer blend of which at least 15%is anionic monomer. The polymer (b) preferably has an intrinsicviscosity of at least 8 dl/g, preferably between 10 and 30 dl/g,especially between 10 and 15 dl/g. The amount of polymer (b) present inthe aqueous composition is below 1.9 wt. % based on total weight ofcomposition, preferably below 1.0 wt. %, more preferably below 0.5 wt.%. The process is particularly effective if the amount of polymer (b)present in the aqueous composition is below 0.2 wt. % based on weight ofcomposition, preferably below 0.15 wt. %. The process is more effectiveif the composition used comprises polymer (b) in an amount between 0.05wt. % and 0.1 wt. % based on total weight of composition. The preferredtypes of polymer (b) include polymers formed from water soluble monomerblend comprising of between 20 and 50 wt. % anionic monomer, preferably25 to 30 wt. %. Particularly preferred polymers for the process arecopolymers of acrylamide with acrylic acid, or alkali metal or ammoniumsalt thereof. In another preferred aspect of the process the aqueouscomposition is prepared by adding the polymer (b) the form of a powderto the aqueous solution of inorganic water-soluble compound.

In the process of applying a fertiliser the composition should haveviscosity which renders the composition easy to handle. It should inparticular be easy to handle (ie preferably pumpable, pourable orsprayable) in the equipment which is presently used for spraying. Thepolymer may be added to the fertiliser at the facility of the fertilisermanufacturer and thus the viscosity should be low enough that theresulting solution can be handled by equipment presently in place insuch facilities. Preferably viscosity is below 3,000 cPs, morepreferably not more than 1,000 cPs. In particular it is not more than500 and especially not more than 250 cPs. Particularly preferably it isnot more than 100 cPs. Usually it is in the range of 5 to 50 cPs,preferably 10 to 30 cPs, more preferably in the range 15 to 20 cPs. Inthis specification viscosity is measured using a Brookfield LVTviscometer using spindle 4 at 30 rpm.

A further aspect of the invention relates to a process of applying aherbicide or a pesticide to an area of land or a crop area comprisingmixing water, said herbicide or pesticide and a composition comprisingwater, in solution,

a) an inorganic water-soluble compound in an amount of at least 10%,

b) an anti-drift agent which is a water soluble anionic polymer ofintrinsic viscosity at least 6 dl/g which is formed from water solublemonomer or monomer blend,

characterised in that the polymer (b) is present in an amount up to 1.9wt. % based on weight of composition,

and then spraying the mixture.

In a preferred aspect of the process of application of pesticide orherbicide, water is pumped through a feed ducting and a mixing zone to aspray manifold supplying one or more spraying devices by which the wateris sprayed onto a crop area and the aqueous composition as defined inclaim 1 is metered into the water at or before the mixing zone, whereinthe inorganic salt is a fertiliser or herbicide adjuvant.

In the process of applying a pesticide or herbicide the polymer (b) ispreferably formed from water soluble monomer or monomer blend of whichat least 15% is anionic monomer. The polymer (b) preferably has anintrinsic viscosity of at least 8 dl/g, preferably between 10 and 30dl/g, especially between 10 and 15 dl/g. The amount of polymer (b)present in the aqueous composition is below 1.9 wt. % based on totalweight of composition, preferably below 1.0 wt. %, more preferably below0.5 wt. %. The process is particularly effective if the amount ofpolymer (b) present in the aqueous composition is below 0.2 wt. % basedon weight of composition, preferably below 0.15 wt. %. The process ismore effective if the composition used comprises polymer (b) in anamount between 0.05 wt. % and 0.1 wt. % based on total weight ofcomposition. The preferred types of polymer (b) include polymers formedfrom water soluble monomer blend comprising of between 20 and 50 wt. %anionic monomer, preferably 25 to 30 wt. %. Particularly preferredpolymers for the process are copolymers of acrylamide with acrylic acid,or alkali metal or ammonium salt thereof. In another preferred aspect ofthe process the aqueous composition is prepared by adding the polymer(b) the form of a powder to the aqueous solution of inorganicwater-soluble compound.

Preferably the quantity of herbicide would be in the range 1 to 5 wt. %,more preferably 2 to 3 wt. %, most preferably around 2.5 wt. %. Forinstance a diluted fertiliser composition to be sprayed contains asystemic herbicide, preferably glyphosate in an amount up to 10 wt. %,preferably 1 to 5 wt. %, more preferably 2 to 3 wt. %, most preferablyaround 2.5 wt%.

Typically the diluted aqueous fertiliser composition to be sprayedcomprises up to 10 wt. % fertiliser and up to 10 wt. % additionalagricultural chemical, which is preferably a herbicide or a pesticide,especially a herbicide, such as a systemic herbicide, which is inparticular glyphosate.

A preferred diluted aqueous fertiliser composition to be sprayedcomprises 1 to 5 wt. % more preferably 2 to 3 wt. %, especially around2.5 wt. % of the aqueous fertiliser concentrate and 1 to 5 wt. %additional agricultural chemical, which is for instance a herbicide orpesticide, preferably a herbicide, more preferably a systemic herbicidemost preferably glyphosate or glufosinate.

One preferred aspect of the invention is a diluted fertilisercomposition to be sprayed comprises ammonium sulphate solutionconcentrate (AMS) in an amount up to 10 wt %, preferably 1 to 5 wt. %,more preferably 2 to 3 wt. %, most preferably around 2.5 wt. % andglyphosate in an amount up to 10 wt. %, preferably 1 to 5 wt. %, morepreferably 2 to 4 wt. %, most preferably around 2.5 wt. %. Aparticularly preferred diluted composition to be sprayed comprisesammonium sulphate solution concentrate (AMS) in an amount up to around2.5 wt. % and glyphosate in an amount up to around 2.5 wt. %.

A further aspect of the invention relates to a process of applyingfertiliser to an area of land comprising spraying water to which hasbeen added an aqueous composition comprising water, in solution, a) aninorganic water-soluble fertiliser in an amount of at least 10%, a watersoluble anionic polymer of intrinsic viscosity at least 6 dl/g which isformed from water soluble monomer of monomer blend, characterised inthat the polymer (b) is present in an amount up to 1.9 wt. % based onweight of composition. In the process the polymer (b) is preferablyformed from water soluble monomer or monomer blend of which at least 15%is anionic monomer, preferably 20 and 50 wt. %, most preferably 25 to 30wt. %. Furthermore in a more preferred process the polymer (b) desirablyhas an intrinsic viscosity of at least 8 dl/g, more preferably between10 and 30 dl/g, especially between 10 and 15 dl/g.

In a particularly preferred the process the polymer (b) is present in anamount below 1.0 wt. % based on total weight of composition, preferablybelow 0.5 wt. %, even more preferably below 0.2 wt. %, especially below0.15 wt. % and most preferably in the range 0.1 wt. % to 0.05 wt. %. Ina particularly preferred process the polymer (b) is a copolymer ofacrylamide with acrylic acid, or alkali metal or ammonium salts thereof,especially a copolymer of acrylamide with sodium acrylate. In aparticularly preferred process the fertiliser is ammonium sulphate. Inanother particularly preferred process the aqueous composition has beenformed by adding polymer (b) into water in the form of a powder. In themost preferred process of applying fertiliser a herbicide, preferably asystemic herbicide, especially glyphosate is combined with the waterwhich is sprayed. Thus the invention also relates to a method ofimproving the spray drift properties of a fertiliser composition bycombining up to 1.9 wt. %, by weight of composition, of a water solubleanionic polymer of intrinsic viscosity at least 6 dl/g, formed fromwater soluble anionic monomer or monomer blend.

In the process of applying a herbicide or pesticide the compositionshould have viscosity which renders it easy to handle. It should inparticular be easy to handle (ie preferably pumpable, pourable orsprayable) in the equipment which is presently used for spraying. Thepolymer may be added to the inorganic water-soluble compound at thefacility of the manufacturer of the inorganic compound, for example afertiliser manufacturer, and thus the viscosity should be low enoughthat the resulting solution can be handled by equipment presently inplace in such facilities. Preferably viscosity is below 3,000 cPs, morepreferably not more than 1,000 cPs. In particular it is not more than500 and especially not more than 250 cPs. Particularly preferably it isnot more than 100 cPs. Usually it is in the range of 5 to 50 cPs,preferably 10 to 30 cPs, more preferably in the range 15 to 20 cPs. Inthis specification viscosity is measured using a Brookfield LVTviscometer using spindle 4 at 30 rpm.

The invention further relates to a method of improving the spray driftproperties during the spraying of a pesticide or herbicide compositionby the application of a composition comprising water, in solution,

a) an inorganic water-soluble compound in an amount of at least 10% byweight,

b) an anti-drift agent which is a water soluble anionic polymer ofintrinsic viscosity at least 6 dl/g which is formed from water solublemonomer or monomer blend,

characterised in that the water-soluble polymer (b) is present in anamount up to 1.9 wt. % based on weight of composition.

Preferably the inorganic water-soluble compound (a) is a fertiliser orherbicide adjuvant.

In the method of improving the spray drift properties during thespraying of a pesticide or herbicide composition the polymer (b) ispreferably formed from water soluble monomer or monomer blend of whichat least 15% is anionic monomer. The polymer (b) preferably has anintrinsic viscosity of at least 8 dl/g, preferably between 10 and 30dl/g, especially between 10 and 15 dl/g. The amount of polymer (b)present in the aqueous composition is below 1.0 wt. % based on totalweight of composition, preferably below 0.5 wt. %. The method isparticularly effective if the amount of polymer (b) present in theaqueous composition is below 0.2 wt. % based on weight of composition,preferably below 0.15 wt. %. The method is more effective if thecomposition used comprises polymer (b) in an amount between 0.05 wt. %and 0.1 wt. % based on total weight of composition. The preferred typesof polymer (b) include polymers formed from water soluble monomer blendcomprising of between 20 and 50 wt. % anionic monomer, preferably 25 to30 wt. %. Particularly preferred polymers for the process are copolymersof acrylamide with acrylic acid, or alkali metal or ammonium saltthereof. In another preferred aspect of the method the aqueouscomposition is prepared by adding the polymer (b) the form of a powderto the aqueous solution of inorganic water-soluble compound.

The invention relates to a method of improving the spray driftproperties during the spraying of a fertiliser by providing an aqueouscomposition comprising water, in solution,

a) an inorganic water-soluble compound in an amount of at least 10% byweight,

b) an anti-drift agent which is a water soluble anionic polymer ofintrinsic viscosity at least 6 dl/g which is formed from water solublemonomer or monomer blend,

characterised in that the water-soluble polymer (b) is present in anamount up to 1.9 wt. % based on weight of composition and wherein theinorganic water soluble compound is the fertiliser.

In the method of improving the spray drift properties during thespraying of a fertiliser the polymer (b) is preferably formed from watersoluble monomer or monomer blend of which at least 15% is anionicmonomer. The polymer (b) preferably has an intrinsic viscosity of atleast 8 dl/g, preferably between 10 and 30 dl/g, especially 10 and 15dl/g. The amount of polymer (b) present in the aqueous composition isbelow 1.0 wt. % based on total weight of composition, preferably below0.5 wt. %. The method is particularly effective if the amount of polymer(b) present in the aqueous composition is below 0.2 wt. % based onweight of composition, preferably below 0.15 wt. %. The method is moreeffective if the composition used comprises polymer (b) in an amountbetween 0.05 wt. % and 0.1 wt. % based on total weight of composition.The preferred types of polymer (b) include polymers formed from watersoluble monomer blend comprising of between 20 and 50 wt. % anionicmonomer, preferably 25 to 30 wt. %. Particularly preferred polymers forthe process are copolymers of acrylamide with acrylic acid, or alkalimetal or ammonium salt thereof. In another preferred aspect of theprocess the aqueous composition is prepared by adding the polymer (b)the form of a powder to the aqueous solution of inorganic water-solublecompound.

The following examples illustrate the invention.

EXAMPLE 1

A range of Sodium acrylate/acrylamide copolymers with a range of IVs andanionicities is assessed for solubility at 0.1% w/w concentration in 32%ammonium sulphate solution. In each test the polymer in powder form ismixed with ammonium sulphate solution in a glass jar and then tumbledfor several hours. The results are shown in Table 1

TABLE 1 Anionic content Polymer (wt. %) IV Solubilty A 28 11.5 Soluble B48 23.2 Soluble C 47 11.6 Soluble D 47 14.4 Soluble E 84 12.2 Soluble F95.5 11.0 Soluble G 100 13.7 Soluble

EXAMPLE 2

A range of sodium acrylate / acrylamide copolymers with a range of IVsand anionicities are assessed for anti-drift properties. For each testeach polymer is added at different concentrations to a 32% ammoniumsulphate solution and tumbled until the polymer has dissolved to form anaqueous concentrate. In each case 2.5 ml of concentrate is mixed with 95ml water and 2.5 ml of a commercially available glyphosate formulationcontaining 480 g/l isopropylamine salt of glyphosate to form a dilutedcomposition ready for spraying. The diluted composition is sprayedthrough a 110° flat fan nozzle at a pressure of 3 bar and a height of 15cm above an absorbent bed. The reduction of the spray angle over anequivalent composition in the absence of polymer is measured. Theincrease in spray angle reduction is measured as the polymer dose isdoubled. The results are shown in Table 2.

Adequate spray drift control is determined by a reduction of at least3%, preferably between 4 and 15 %, most preferably in the range of 5 to10%.

EXAMPLE 3

Samples of aqueous fertiliser concentrate comprising either an anionicor a cationic polymer are assessed for storage stability over 2 days.Cationic polymers are acrylamide copolymers with dimethylaminoethylacrylate, methyl chloride quaternary salt. Anionic polymers areacrylamide copolymers with sodium acrylate. The results are shown inTable 3.

TABLE 2 Concentration of % Increase in polymer in Spray Spray AngleAnionic aqueous Angle Reduction as Poly- Content Concentrate ReductionConcentration is mer (wt. %) IV (wt. %) (%) doubled A 28 11.5 0.05 5.14.4 0.10 9.5 0.15 14.0 B 48 23.2 0.05 5.5 7.2 0.10 12.7 0.15 28.0 C 4711.6 0.10 8.8 3.6 0.20 12.4 D 47 14.4 0.10 8.8 9.4 0.15 12.4 0.20 18.2 E84 12.2 0.10 4.5 16.3 0.15 11.3 0.20 20.8 F 95.5 11.0 0.10 5.6 16.9 0.157.5 0.20 22.5 G 100 13.7 0.10 5.3 19.9 0.15 13.1 0.20 25.2

TABLE 3 Polymer Stability over 2 Polymer % Ionic Concentration (%) daysH 73% cationic 1 gelatinous mass formed 1.5 gelatinous mass formed 2gelatinous mass formed I 76% cationic 1 gelatinous mass formed 2gelatinous mass formed J 65% anionic 2 stable 5 stable 10 stable K 95.5%anionic 1 stable L 67% anionic 1 stable

EXAMPLE 4

Winter barley plants were sown in peat trays under growing roomconditions. At the ⅔ leaf growth stage, the plants were sprayed with arange of treatments (detailed below) using a compressed air stationarysprayer. The volume of water used was equivalent to 250 litres perhectare at a pressure of 3 bar, through a Lurmark 015 F80° flat fannozzle.

Treatments

1. Cipac D water—control.

2. Glyphosate.

3. Glyphosate+Ammonium sulphate (34%).

4. Glyphosate+Ammonium sulphate(10%).

5. Glyphostae+Ammonium sulphate(34%)/Polymer X (Copolymer ofacrylamide/acrylic acid (4.5/95.5 wt./wt.) (0.1% by weight offormulation).

6. Glyphosate+Ammonium sulphate (10%)/Polymer Y (Copolymer ofacrylamide/acrylic acid (72/28 wt./wt/) (1.0% of formulation).

The glyphosate used was a proprietary glyphosate formulation containing480 g/l isopropylamine salt of glyphosate, equivalent to 360 g/lglyphosate. The level of Glyphosate used was equivalent to 1.0 litre perhectare. The ammonium sulphate (AMS) Polymer X formulation was used at arate equivalent to 9.38 litres per hectare, and the AMS/Polymer Yformulation used at a rate equivalent to 1.88 litres per hectare.Treatment (3) was used at the same dose rate as treatment (5) i.e.equivalent to 9.38 litres per hectare, and treatment (4) was used at thesame dose rate as treatment (6) i.e. equivalent to 1.88 litres perhectare.

Cipac D water (containing 342 ppm Ca as calcium carbonate) was usedthroughout the trial and each treatment was replicated four times.

Three days after application of treatments, the plants were cut justabove the growing point. The percentage re-growth was assessed 9 daysafter the application. The percent kill assessment was made 21 daysafter the application of treatments.

The percentage re-growth and percentage kill of the plants for each ofthe treatments are given in Table 4.

TABLE 4 1 2 3 4 5 6 Glypho- Glypho- sate + sate + Glyphosate +Glyphosate + Con- Glypho- AMS AMS AMS 34% + AMS 10% + trol sate 34% 10%Polymer X Polymer Y Re- 99 105 10 19 6 15 growth after 9 days (%) Kill 57 68 43 76 51 after 21 days (%)

As can be seen from the results the polymers clearly enhance theefficacy of the Glyphosate formulation above that of the AMSformulations alone.

What is claimed is:
 1. A process of applying a herbicide or a pesticideto an area of land or a crop area comprising mixing water, saidherbicide or pesticide and a composition comprising water, in solution,a) an inorganic water-soluble compound in an amount of at least 10% byweight, b) an anti-drift agent which is a water soluble anionic polymerof intrinsic viscosity at least 6 dl/g which is formed from watersoluble monomer or monomer blend, characterised in that the polymer (b)is present in an amount up to 1.9 wt. % based on weight of compositionand then spraying the mixture.
 2. A process according to claim 1 inwhich water is pumped through a feed ducting and a mixing zone to aspray manifold supplying one or more spraying devices by which the wateris sprayed onto an area of land or a crop area and an aqueouscomposition comprising water, in solution, a) an inorganic water-solublecompound in an amount of at least 10% by weight, b) an anti-drift agentwhich is a water-soluble anionic polymer of intrinsic viscosity at least6 dl/g which is formed from water soluble monomer or monomer blend,characterized in that the polymer (b) is present in an amount up to 1.9wt. % based on the weight of the composition is metered into the waterat or before the mixing zone, wherein the inorganic water-solublecompound (a) is either a fertilizer or herbicide adjuvant and isselected from the group consisting of ammonium nitrate, ammoniumsulphate, mono ammonium phosphate, diammonium phosphate, mono potassiumphosphate, dipotassium phosphate, polyphosphate salts, potassiumchloride, potassium sulphate and calcium nitrate.
 3. A process accordingto claim 1 in which the polymer (b) is formed from water soluble monomeror monomer blend of which at least 15% is anionic monomer.
 4. A processaccording to claim 1 in which the polymer (b) has an intrinsic viscosityof at least 8 dl/g.
 5. A process according to claim 1 in which thepolymer (b) is present in an amount below 1.0 wt. % based on totalweight of composition.
 6. A process according to claim 1 in which thepolymer (b) is present in an amount below 0.2 wt. % based on weight ofcomposition.
 7. A process according to claim 1 in which the polymer (b)is present in an amount between 0.1 wt. % and 0.05 wt. % based on totalweight of composition.
 8. A process according to claim 1 in which thepolymer (b) is formed from water soluble monomer or monomer blendcomprising of between 20 and 100 wt. %, anionic monomer based on totalweight of polymer.
 9. A process according to claim 1 in which theinorganic water-soluble compound is either a fertilizer or herbicideadjuvant and is selected from the group consisting of ammonium nitrate,ammonium sulphate, mono ammonium phosphate, diammonium phosphate, monopotassium phosphate, dipotassium phosphate, polyphosphate salts,potassium chloride, potassium sulphate and calcium nitrate.
 10. Aprocess according to claim 1 in which the inorganic water-solublecompound is ammonium sulphate.
 11. A process according to claim 1 inwhich the polymer (b) is a copolymer of acrylamide with acrylic acid, oralkali metal or ammonium salt thereof.
 12. A process according to claim1 that improves spray drift properties during the spraying of apesticide or glyphosate by the application of a composition comprisingwater, in solution, a) an inorganic water-soluble compound in an amountof at least 10% by weight, b) an anti-drift agent which is a watersoluble anionic polymer of intrinsic viscosity at least 6 dl/g which isformed from water soluble monomer or monomer blend, characterised inthat the polymer (b) is present in an amount up to 1.9 wt. % based onweight of composition to said pesticide or herbicide prior to spraying.13. A process for the preparation of the composition comprising water,in solution, a) an inorganic water-soluble compound in an amount of atleast 10% by weight, b) an anti-drift agent which is a water solubleanionic polymer of intrinsic viscosity at least 6 dl/g which is formedfrom water soluble monomer or monomer blend, characterised in that thepolymer (b) is present in an amount up to 1.9 wt. % based on weight ofcomposition in which the polymer (b) is added in the form of a powder toan aqueous solution comprising at least 10 wt. % wherein the inorganicwater-soluble compound (a) is either a fertilizer or herbicide adjuvantand is selected from the group consisting of ammonium nitrate, ammoniumsulphate, mono ammonium phosphate, diammonium phosphate, mono potassiumphosphate, dipotassium phosphate, polyphosphate salts, potassiumchloride, potassium sulphate and calcium nitrate.